Paintings from Sunset Series by Spence Munsinger, Color Field + Blank White Canvas + Realism + Contemporary Abstract Art, original paintings for sale

"You have to have an idea of what you are going to do, but it should be a vague idea..."
― Pablo Picasso

images of art for print reproduction


What does it take to produce a reproduction of a painting? Not an image for a website, but an image of high enough quality to use as a print reproduction? At full size or as close to full size as practicable?

weathervane detail

Two measurements – two sides of the process:

  • DPI (dots per inch) is the measurement on the printer itself. That’s your print output.
  • PPI (pixels per inch). Pixels per inch is the measurement of the image resolution within the file.

Differences between DPI and PPI are interpolated in software – like upsizing or downsizing an image in Photoshop, done on the fly. Upsizing, making larger, is prone to errors, and is better done in Photoshop rather than by the printer driver; downsizing is not.

The acceptable file size for full print reproduction of a 30″ x 40″ painting (300 pixels per inch (PPI)) is 9000 x 12000 pixels. 240 PPI is usually acceptable. I just took a 6 x 7 cm medium format color negative, scanned in a Nikon film scanner at 4000 DPI/PPI, and with cropping the final resolution image is 8964 x 11016 pixels, and a whopping 493.22 MB in size (16bit). Increasing the resolution of the height from 11016 to 12000, and then cropping back to 9000 for the width will hit that target. I’ll increase the resolution in Photoshop to 12000 using bicubic smoother. The final file gets saved separately from the original scan file. Both are TIFF files at this stage, uncompressed.

The combination of Mamiya medium format RZ67 camera and Nikon film scanner result in an 89 megapixel image. Ten times the resolution of my Canon 30D digital. That’s exactly why film rules for this application…

Paintings are not photographs. They are imprecise by the nature of the medium. The final file will print very well at 300 DPI on canvas, or heavy paper.

The negative is scanned at 4000 DPI (sorry – really Pixels per Inch at this stage, but Nikon uses DPI, as does all the scanner literature). I multiscan the negative 4x to 8x (reduces digital noise, at least some). The original scan file is opened in Photoshop (slowly – 565 MB file). I use Neat Image, a noise reduction program to clear the digital noise out – it works both as a standalone program and a Photoshop plugin, and produces outstanding results in cleaning digital files, whether scans or digital photographs. Get the resolution correct, sharpen for printing, save the file, and that’s it.

I took a test roll of ten shots of a single painting to get exposure correct – in the lighting, with the filter and set up exactly as the actual shots would be. I varied the exposure from measured light amount (1-1/2 seconds at f16) upward 4 stops and downward 4 stops. It turned out the measured exposure was over-exposed, and dropping a full f stop down (less light) created a much better image. I also found that I needed to move closer to the painting, filling more of the frame, to get the largest capture possible (less cropping, more actual pixels).

This last Friday evening I took the test roll, ten shots, from set up to photographing to development of the film and hanging it up to dry. Saturday I scanned the resulting negatives, parsed through and determined the ideal exposure. I then took three rolls of 10 exposures each, developed all three rolls, hung up to dry, and broke down and packed away the setup.

Total cost in film and chemicals – $36. Equipment costs to photograph, develop, scan, adjust and store the images – $5500.00. Having control over the quality of the final image files – priceless…

weathervane section

Scanning and adjusting the images will take a couple of weeks. Test prints to validate the image – another week. I’ll post some more detail sections as I work through these.


— spence


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